Heat Under Hood

[c_forshaw]

I have had the hood off for several weeks doing some engine work. After moderate driving, with the hood off, I have noticed the amount of heat that is generated in the engine compartment. Is there any way to evacuate the heat, or is it evacuated itself while driving?

[boxhead]

The only way you can extract more heat is to make holes toward the rear of the engine bay so it can blow out whilst driveing.
are the holes where your louvers are cut out?
I have seen some cars where the louvers have been fitted over the area where the hole should be.
also are your louvers facing the correct way?
alot of under bonnet heat is generated in most cars.
if your engine timing is incorect or your fuel mixture wrong then this will add heat to your engine and exhaust system.

[Jack21]

Also, ceramic coat your headers inside and outside. Better still, do your sidepipes outside too. This will dramatically reduce the underhood heat generated by your exhaust system. Had I known this was going to work as well as it does, I would have used less insulation in the foot boxes. With double face aluminum padding in the front end of the pass compartment, and the ceramic coated headers, the footboxes and firewall don't even get warm.

[Mr.Fixit]

Ceramic coated headers do help quite a bit. So does 11:1 compression, 9:1 motors run too hot and are too weak for my tastes. Also make sure your timing isn't too retarded. A good fan that moves at least 1000cfm of air helps keeps everything from cooking. It's also a good idea to glue heat reflective blanket on the underside of the fenders just over where the headers exit to meet the sidepipes to prevent the fiberglass from getting "wavy"

[AdamIsAdam]

Old thread, but still have questions...

I'm about to buy a car that has ceramic coated headers, but I do not think the side pipers are coated, just polished stainless. Would it help reduce heat coming into the cabin to coat the pipes or make no difference? And I assume it makes no difference in how bad the burn on her calf will be when she gets out without stepping over them, right?

Engine is a 347 about 450hp.
Car is FFR MKIV

TIA,
Adam

[Alfa02]

We call them "Snake Bites" The burn doesn't last as long, as trying to get the brunt skin off the pipe I thought I was being very careful, it would take years to get one, but one day just moving aside to let another owner by the car, I touched mine, YES, it hurts, and yep it "Left a Mark" Cheers Tom.

[patrickt]

Originally Posted by AdamIsAdam

I'm about to buy a car that has ceramic coated headers, but I do not think the side pipers are coated, just polished stainless. Would it help reduce heat coming into the cabin to coat the pipes or make no difference? And I assume it makes no difference in how bad the burn on her calf will be when she gets out without stepping over them, right?

Coating the side pipes will not change the heat coming in to the cabin -- especially if you're moving. Stainless pipes will burn your leg worse than coated pipes will, but coated pipes will still give you a bad burn if you don't yank your leg off them quickly. I keep a 2' x 2' piece of welding blanket behind my seat and drape it over the pipes before my passenger gets out. See this thread: Rick Lake - Thanks for this Tip! I haven't burned my leg in the last ten years, but I have on occasion touched my leg to the pipes -- but I'm at a point now where I can yank it off fast enough that the burn is pretty much the equivalent of a sun burn now.

[AdamIsAdam]

Thanks. I had the same idea about a welding blanket, so seeing that pic and seeing it in action is extremely helpful! THANKS!

I heard that the FFR (at least the MKIII) allows the heat from the side pipes to come inside the cabin on the side and heat things up. I'm not sure it's the same on the MKIV, but that's what I heard. Right now, I can't imagine I care about that, but it's January in NY, so it's hard to imagine being too hot at all. lol

[patrickt]

If you want to ease the heat down a bit, putting these in your fender wells will make a good first project.

[AdamIsAdam]

Be gentle, remember, I'm new here...

Is this the after picture, showing a ventilation hole that didn't previously exist? is that what I'm looking at? Interesting idea. I guess it lets heat out and cool air in.

[patrickt]

Originally Posted by AdamIsAdam

Be gentle, remember, I'm new here...

Is this the after picture, showing a ventilation hole that didn't previously exist? is that what I'm looking at? Interesting idea. I guess it lets heat and as well as cool air in.

Yes, non-ventilated fender wells will look just like the fender well that's in whatever car is currently sitting in your driveway. When the puller fan kicks on in a Cobra, that is located on the engine side of the radiator, the under hood heat literally billows out through those vents in to the wheel wells. That modification is not terribly difficult and I would bet that FFR probably sells them to fit.

[Dwight]

I love stainless pipes but in my opinion they should be ceramic coated. In my car ceramic coating is a must.

Stainless radiates heat for a long time after the motor is turned off. Chrome pipes are just as bad.

Way to hot.

Ceramic coating is a must. IMHO

I have a temperature sensor on my radiator fan that allowed the fan to run a few minutes after I shut down the motor. I now use a 210 on & 195 off sensor, wired behind the ignition switch, so it will cool the motor after I park the car.
This blows the hot air from under the hood till everything cools down a little.

[MLI]

To help prevent passengers burned calf’s from my 427’s side pipes. I bought on Amazon: Hensway High Temp 14X24X1/4 Felt Carbon Fiber blanket for $ 14.99.
I often wear shorts and only use it for family and friends who want a ride in my Kirkham. Blanket lives behind the passenger seat. No burns in 3000 miles in 2019. I did open drivers door, when first purchased, and burned my fingers putting it over pipe. At 81 I’m hoping I can remember to be carful on my side but did scratch the rear fender with my watch clasp so now watch that also.
Jerry

[patrickt]

Originally Posted by MLI

At 81 I’m hoping I can remember to be carful on my side...

That is absolutely spectacular.